Turbo I4 Diagnostic Troubleshoot Excessive Crankcase Pressure

[enkeivette]

All in the title. Turbo I4 has an issue with excessive crankcase pressure.

The head was warped so bad it had to be resurfaced but the cams still rocked from the head being bowed. So a crack in the head was a definite suspect. We pulled the head, but cannot see any cracks. And the area between the combustion chamber and the crankcase is THICK, which makes me second guess the diagnosis.

Piston walls look kinda shiny, but there is still evidence of cross hatching. Plus there was no issue with ring blow-by before the over-heating/ HG failure/ head warpage issue. Which makes me second guess poor ring sealing.

No blow by into the coolant. No oil contamination. HG was new MLS, no evidence of blow by into a crank case pressure port from the HG.

Ideas?

[94cobra69ss396]

How can you tell it has excessive crankcase pressure?

[enkeivette]

It is pushing oil out everywhere, intake, valve cover seal, spark plug seals (on top), pcv popping out.

It is a symptom, mechanic confirmed.

[94cobra69ss396]

I've only seen that with a blown head gasket on a boosted engine.

[Damian]

Is the PCV even working?

[enkeivette]

Not under boost, it should really be hollowed out and routed to the intake. I did that with mine, it helped a lot.

[enkeivette]

I've only seen that with a blown head gasket on a boosted engine.

The crankcase port that runs from the block through the head is only a 1/2" single port. Not likely, but possible.

[Damian]

Not under boost, it should really be hollowed out and routed to the intake. I did that with mine, it helped a lot.

The Typhoon actually has 2 PCVs on the same valve cover. One goes to the TB, the other goes to the intake pipe before the turbo. Under boost, there is enough suction on the intake to pull a vacuum on the vent.

[enkeivette]

Nice

[Damian]

Maybe try something like that with this car?

[94cobra69ss396]

Where does he have the PCV valve at and where is it connected? If you have the PCV valve in a valve cover (or like the Cobra does, in the lower intake direct to the valley of the block) with the other end connected to the intake manifold vacuum then if you gut the PCV valve you will push boost into the crankcase.

[enkeivette]

Where does he have the PCV valve at and where is it connected? If you have the PCV valve in a valve cover (or like the Cobra does, in the lower intake direct to the valley of the block) with the other end connected to the intake manifold vacuum then if you gut the PCV valve you will push boost into the crankcase.

Valve cover, his isnt gutted so it closes when there is boost. I think he might have an intake suction tube also though.

And in the VETTE its not connected to vacuum, its in front of the blower, only suction all the time.

[enkeivette]

Maybe try something like that with this car?

Its too much crankcase pressure, need to fix the underlying issue. Head is already being replaced. Was trying to see if re-ringing was also a good idea, or unwarranted

[94cobra69ss396]

Excessive crankcase pressure comes from either a blown head gasket or bad rings/ring seal. Somehow the cylinder pressure is escaping.

[Damian]

Either that or the PCV system isn't working at all. Maybe gunked up lines, or even the PCV itself is gunked up.

[enkeivette]

Either that or the PCV system isn't working at all. Maybe gunked up lines, or even the PCV itself is gunked up.

It was excessive